Raster is a data format consisting of regular grids of values, usually stored in an image-like format.

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1answer
918 views

How to add tree height values to raster / vector data?

I am new to working with raster data and I am trying to teach myself a few things. I have what I think is a simple problem but I can't seem to figure this one out after a few hours of searching Arc ...
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1answer
100 views

Why do the raster band values have different values than the raster statistics?

I am working on a raster file (1 Band). According to the raster metadata, my minimum value is 0 and maximum is 7458. This seems to be confirmed by the Style options that return some category values ...
3
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2answers
647 views

How can I get my raster analysis to produce a larger extent in ArcGIS

Ok so the situation is as follows. I have an vector shapefile and within that area there are three points. I converted the points into raster and now I want to do a Euclidean distance analysis in ...
2
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1answer
578 views

Find maximum and minimum value in a list of raster

I trying to write a standardisation script that standardises each raster dataset in a list of rasters by the highest and lowest values found in the list of rasters. The standardisation code is as ...
7
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5answers
3k views

Continuous color band for a raster legend in QGIS composer legend

I'm looking for a way to insert continuous colour legend for a raster layer. I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values ...
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1answer
86 views

Extract information of a raster overlayed on another raster with a lower resolution directly in python

I have two aligned rasters with the same extent, one has a resolution of 5 meters and the other of 125 meters. I would like to place the 5 meter one over the 125 meter one and assign to these smaller ...
2
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1answer
159 views

Map algebra for loop

I have never coded in Python before and I am trying to loop a simple map algebra equation across 365 rasters. I am trying to calculate total water flow over cells but in the raster I have a negative ...
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1answer
589 views

How to create graph out of two layers using ArcGIS 10.1 for Desktop?

I would like to create a graph of two layers I have. on one hand its the land price of a certain area and on the other a layer with a crime rate. first of all, the layer with the land prices doesnt ...
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1answer
2k views

Fill sinks error in arcHydro

I am working on a project that is modeling runoff at a county level. The DEM used is lidar derived and has a 5 ft resolution. The general workflow I am flowing is Sink evaluation Sink Selection (to ...
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0answers
103 views

How to extract raster using corresponding polygon using ArcPy?

I have to perform a simple raster extraction, but I can't find the way to do it. In a polygon layer, I have watersheds with their ID's. And in a folder, I have rasters, each one corresponding to a ...
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1answer
255 views

How to combine Boolean and Fuzzy logic?

So I have a set of 5 Fuzzy Memberships and a polygon feature class, to which I already added a yes/no field. For the final map, I need to combine/overlay all Fuzzy Memberships and the rasterized ...
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3answers
1k views

Topography: How to get the x,y,z coordinates of highest or lowest point/pixel of a raster GIS?

Given a .tiff topographic raster image with mountains and deep sea, I am looking for the x,y,z specifics of the highest or lowest point. The x,y,z values being: altitude (z-coordinate) latitude ...
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3answers
857 views

Gdal: how to get the max and min altitudes of my topographic raster?

Given a .tiff topographic raster image. How to get the altitudes of the highest and lowest point/pixel ?
3
votes
3answers
2k views

How to extract X Y coordinates and RGB from pixels using python in QGIS?

I'm trying to white a Python plugin in QGIS (2.2) to get, for each pixel of a raster image, its X Y coordinates, as well as, its RGB (3 bands) values. At first I opened the raster file using: rlayer ...
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0answers
42 views

How to modify extent (layer) for Fuzzy Membership analysis?

When applying the Fuzzy Membership, how do I modify the extent (layer) to which it is applied? I don't mean showing the extent, but changing the values (mid point & spread) to a different layer? ...
6
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1answer
1k views

R raster Package Moran's I interpretation

I am using raster package to calculate the local Moran's I . The example gives the range of Moran's I between - 1 to 2.47. On my own data I have see the value range -3.070423 - 7.228558 How can ...
3
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4answers
8k views

Combine overlapping rasters with priority to values of specific rasters?

I have 5 rasters that cover a large area. I want to combine all 5 into 1 raster. Each raster has data for portions of the total area that none of the other rasters cover. Raster C overlaps A,B and D. ...
0
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0answers
31 views

How can I remove dipoles from rasterlayer in QGIS 2.2?

I work with geomagnetic survey data. When convertet into a rasterlayer, every object with a high magnetic potential (for exampel an iron-nail on the surface) is shown as very sharp anomalie called ...
7
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1answer
369 views

How can I conduct Geographically Weighted Analysis using an exponential decay function?

I have some points (representing 30 study sites) and I want to calculate the weighted mean of several variables (landscape layers) using a negative exponential decay (weights function) to give more ...
2
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1answer
116 views

Zonal Statistics Freezing QGIS 2.2

Running on Windows; 8gb memory, 500gb HD, i5 cpu; Raster file: 250mb I am having a problem with zonal statistics advancing past 17%. I am trying to run statistics on a crop grown in certain counties. ...
0
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0answers
223 views

I had an error in Gdalwarp and i don't know the reason

I was trying to warp a raster using a mask and shift it before clipping but when i exectute the command bellow in Qgis/PyQt using QProcess: gdalwarp -s_srs "+proj=merc +a=6378137 +b=6356752 ...
2
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2answers
790 views

Mask image based on no-data pixels in another image with different projection - GDAL or Python

I've got a land cover image which covers the whole globe, and a satellite image which covers a very small part of the globe. These two images have different projections, co-ordinate systems and pixel ...
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0answers
66 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
3
votes
1answer
752 views

Interpolating contour lines from TIN-model vs Grid in ArcGIS for Desktop?

I am a complete beginner in GIS and taking a class right now, and we are doing some assignments in ArcGIS - ArcMap. In one of them we were given a shapefile with heightpoints. These had been manually ...
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0answers
73 views

problem saving GRID to .img keeping original names (export by attributes)

I am really new in Python programming. I try to make a loop for Extract by Attributes tool in ArcGIS 10.1. I have a huge dataset of raster (760pc) and I want to extract a specific value. This part of ...
2
votes
1answer
420 views

Plot a Raster in R with white space for NA values

I want to produce a .png of a raster with background values plotted as white space. Below you can see the current state of the plot. As you can tell, the pixels which should contain NA values, ...
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0answers
226 views

Workflow with raster in Qgis 2.2

I'm trying to build a workflow with the Qgis 2.2 processing toolbox. I want to clip a raster layer with a vector layer using the GDAL tool "clip with a layer mask". But it doesn't work. The error ...
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2answers
616 views

References to code IDW algorithm

Hi I'm new to interpolations. I'm looking for documentation to understand how inverse distance algorithm works and how to code it. My intention is to code IDW algorithm in JavaScript to see if it is ...
2
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0answers
70 views

Define uphill side of roads and buildings

I have a big raster of a mountain region and I need to extract the uphill side of roads and buildings, from these elements to the pick of mountains. For a road I know the uphill side changes in ...
4
votes
1answer
651 views

R Raster package loop over pixels

I want to perform a trend analysis for each pixel over it's time dimension. Therefore I wrote a loop over each pixel doing the calculation but this is extremely slow. I am sure there must be a faster ...
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1answer
155 views

How to use USGS Bulk Download on EC2 linux Server?

I am interesting in downloading Landsat 8 rasters to an Amazon EC2 instance and would like to know how to do it. I already install USGS Bulk Download but I do not know how to use it in terminal mode ...
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99 views

write rasters from estudm2spixdf with significant digits

I have estimated my kernels using kernelUD from the adehabitatHS package which produces information from multiple animals as a class estUDm. I am trying to write out from R to get into ArcGIS the ...
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24 views

How do I randomly alter a raster with som correlation

I need to randomly alter an existing raster. The original raster is essentially a topography map that measures its values around a normal distribution ranging between 0.5 and 1.5 The new raster ...
3
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1answer
183 views

Cell Statistics in QGIS

Cell Statistics in ArcGIS will calculate the mean (or statistic of choice) among multiple rasters on a cell-by-call basis. Can QGIS do this? If so, how?
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1answer
1k views

Raster Multiplication - Can't Multiply Sequence by Non-Int of Type “Float”

I am trying to multiply a list of GRID raster datasets using a different value for each raster. The value is in the raster name. Some examples are [wse_1979_5,wse_1980_0,wse_1980_5], where 1979_5, ...
3
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0answers
347 views

Does QGIS support .sld style files for raster layers?

I'm currently looking at the documentation for geoserver, and I'm trying to load a raster and .sld file in QGIS to see if I can edit .sld files for raster layers. The .sld and raster are located here: ...
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2answers
84 views

Arcpy GetRasterProperties returns odd results

I have this simple piece of python code to test whether a raster has integer values or not: res = arcpy.GetRasterProperties_management(ws, 'VALUETYPE') res = res.getOutput(0) ...
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0answers
170 views

Convert raster_stats list output to array / csv file

I usually program in R, but recently I have started to use python for most of my spatial programming. My python skills are still limited, and please excuse the simplicity of the question. I am ...
4
votes
1answer
3k views

Georeferencing an image with GDAL, based on QGIS Georeferencer Plugin

I would like to georeference an image with GDAL. The image already has a spatial reference set (EPSG:31276). For the georeferencing, I have a list of 4 ground control points (also in EPSG:31276). ...
2
votes
1answer
512 views

Extract/Split raster dataset by attribute (OBJECTID)

I have a raster dataset with an attribute table generated from a series of image classification (unsupervised) and processing tools (majority filter + boundary clean). The attribute table shows pixels ...
6
votes
1answer
447 views

GDAL equivalent of ArcGIS Mosaic

The word 'mosaic' is often used for quite different things within the worlds of ArcGIS and GDAL. With GDAL and it's downstream applications like Qgis it is common to see mosaic used in the context ...
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1answer
149 views

Why does a raster with resolution 5x5m not create a grid with these dimensions? [closed]

I created a 5m x 5m raster using ArcGIS 10.0 Spatial Analyst from a point file. As can be seen in the screenshots of the image and the table, the resulting grid has a higher resoluation than is ...
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2answers
711 views

How to show cell values of raster in ArcGIS

I would like to know if it is possible to display a raster cell value in the center of a cell with ArcGIS in the same way that SAGA-GIS does when you zoom in.
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0answers
136 views

Turn vector layer in raster layer based on cost

Hy, I am trying to rasterize some vector layers into raster layers and I know this is possible with QGIS by using the rasterize function in the raster menu but I don't know how to do the following ...
2
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0answers
143 views

Create custom raster pyramid using arcpy in ArcGIS 10.2

I have a arcpy script that runs the Point Density tool several times for the same extent, using the same number of neighborhood cells, but with cell size increasing at an multiple of 2 with each pass. ...
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1answer
118 views

GEOTIFF Binary File with Color Display Issues

I have a GEOTIFF in QGIS that shows values of 0 and 1 and I want the 0 values to have no fill so that background vector layers can show through and so I can easily overlay things in a print composer ...
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0answers
49 views

I want to reproject data from 0-360 to -180 - 180 [duplicate]

I've been downloading data from NOAA in a CRS that goes from 0-360. The rest of my data is in -180 to 180. What's the easiest way to reproject or shift the data in QGIS? It took 30 seconds in ArcMap, ...
1
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1answer
120 views

QGIS combine Vectorlayer and Rasterlayer to one shapefile

I have to create some Thematic Maps, especially Choropleth Maps on Matlab. Therefore i've found a shapefile which I can use, but need to draw some lines there. I've imported my shapefile as a Vector ...
4
votes
3answers
2k views

Per-pixel (statistical) calculations on a raster stack using GDAL

In R, it's relatively trivial to perform per pixel calculations based on a raster stack (e.g., get std.dev for each pixel on a 12 layer GeoTIFF). Unfortunately, the speed is less than desirable when ...
0
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1answer
189 views

gdal's polygonize function (via qgis) is not turning monochrome rasters into readable shapefiles regardless of inversion of color scale

I've tried polygonizing this monochrome bitmap as this: and this: and either way it ends up looking like this when (zoomed in) after gdal's polygonize operation: Is there any way I can tell ...